This invention relates to mounting plates for power tools and more particularly to a universal mounting plate for mounting power tools of a wide variety of designs beneath the working surface of a work bench.
A power tool such as a router or saw usually has threaded holes on its base or mounting ring and is attached to the underside of an insert on a work bench by means of screws or bolts. There is no universal standard for the size or the pattern of holes in the base of the tool and for that reason, the insert in some cases is provided with many holes so that no matter what the pattern of holes in the base, holes can usually be found in the insert in registry with those in the base. In other cases, the inserts are provided with no holes at all and in this case, holes must be drilled in the inserts to line up with the holes in the base of the power tool.
A shortcoming of inserts with many holes is that each hole is a site for waste such as wood shavings, dust and other by-products of whatever operation is being carried out on the work bench. As the waste builds up in the holes, the inserts become more and more bumpy and irregular and difficult to work on. These holes may also prevent the stock on the work bench from sliding easily over the working surface.
A shortcoming of inserts without holes is that time and considerable skill are required to prepare them for attachment to the base of a power tool. The typical user of such tool does not have such skill and it is usually quite inconvenient for him to find a person who does.
I have devised a mounting plate which is used in place of a conventional insert in a work bench. The mounting plate may be connected to the base of a power tool having a wide variation of pattern of holes. Briefly my mounting plate comprises an upper panel having an aperture for receipt of the cutting implement of a power tool such as a bit or a saw. The upper panel is adapted to be received in the opening for an insert formed in the work bench such that the upper surface of the upper panel is flush with the working surface of the bench. The lower surface of the upper panel has a cavity for removable receipt of a sub-panel. The cavity has an upper face which is spaced apart from the upper surface of the upper panel. When the sub-panel is in the cavity, it is substantially immovable. The sub-panel has a number of slots and circular holes for removable receipt of fasteners for inter-connecting the sub-panel and the base of the power tool. The upper surface of the cavity separates the fasteners from the upper surface of the upper panel so that the fasteners do not interfere with the operation of the power tool. The mounting plate has at least one anchor bracket for removably confining the sub-panel within the cavity.
The mounting plate may alternatively have a sub-panel disposed beneath the upper panel and means for securing the sub-panel to the upper panel so that the sub-panel is substantially immovable relative to the upper panel. The sub-panel has a number of holes formed therein for removable receipt of fasteners for interconnecting the sub-panel and the base. The lower surface of the upper panel defines a barrier which separates the fasteners from the upper surface of the upper panel and which confines the fasteners beneath the upper surface.